danielcweeks commented on code in PR #15630: URL: https://github.com/apache/iceberg/pull/15630#discussion_r3150413269
########## format/spec.md: ########## @@ -168,6 +188,35 @@ All columns must be written to data files even if they introduce redundancy with Writers are not allowed to commit files with a partition spec that contains a field with an unknown transform. +### Paths in Metadata + +Path strings stored in Iceberg metadata files are classified as one of two types: + +* **Absolute path** -- A path string that includes a [URI scheme](https://datatracker.ietf.org/doc/html/rfc3986#section-3.1) (e.g., `s3:`, `gs:`, `hdfs:`, `file:`). Absolute paths are used as-is without modification. +* **Relative path** -- A path string that does not include a URI scheme. Relative paths must be resolved against the table's base location before use. + +Prior to v4, all path fields must contain absolute paths. Starting with v4, path fields may contain either absolute or relative paths. Directory navigation symbols (`.` and `..`) and other file system conventions are not supported in relative paths. + +#### Path Resolution + +Path resolution is the process of producing an absolute path from a relative path by combining it with the table's base location. If a path is absolute, it is used as-is. If a path is relative, it is concatenated with the table location to produce an absolute path: + +* If the path contains a URI scheme, it is absolute and is used without modification. +* If the path does not contain a URI scheme, the resolved path is the table location followed by the relative path. + +Paths used as prefixes must not end in a path separator. The relative portion is appended to the prefix without introduction of any additional separator characters. Review Comment: We don't define or use separators in the path resolution on purpose (so that we don't have to define what the path separator is). Some object storage doesn't require any path separator, so we want to remain agnostic about separators. If you want a separator between the table location and the relative portion, then it should be prepended to the relative portion. This holds true for `write.data.path` as well, so you would use `/data` if you want a path component relative to the table location. Note, it also does not end in a path separator and the relative parts in the metadata should prefix a separator is one is expected. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
